Pumping unit for a liquid medium

Abstract

A pumping unit is provided with a pump that is partially disposed in a stator of an electric motor. The rotor is at an opposite end from the pump and is connected to the pump shaft to drive it for fluid flow. The pump shaft can be positioned in a central bore of the rotor and connected thereto via a meshing gear.

1. A pumping unit for a liquid medium comprising: an electric motor having a rotor and a stator, said rotor having a central bore;
 a pump for conveying the liquid medium and being operably connected to and driven by said electric motor, said pump being at least partially radially inside of said stator, said pump having a shaft and an eccentric internal geared wheel, said shaft having a pinion opposite to and meshing with said eccentric internal geared wheel; 
 a housing enclosing said electric motor and said pump, wherein said rotor is on a first end of the pumping unit that is opposite to said pinion and said eccentric internal geared wheel of said pump, and wherein said rotor is resistant to rotation with respect to said shaft by a first segment of said shaft that extends axially into said central bore of said rotor; and 
 an annular-shaped intermediate space between said rotor and said stator, wherein said housing has first and second end sides that are axially opposed to each other, wherein said first end side has an inlet for the liquid medium, wherein said second end side has an outlet for the liquid medium, and wherein the liquid medium flows from said inlet axially along said stator through said annular-shaped intermediate space through said pump and out of said outlet. 
 
   
   
     2. The pumping unit of  claim 1 , further comprising a meshing gear connected to said rotor on an end of said rotor that is opposite to said pump, wherein said meshing gear engages with said shaft thereby allowing said rotor to drive said shaft. 
   
   
     3. A pumping unit for a liquid medium comprising: an electric motor having a rotor and a stator, said rotor having a meshing gear connected thereto;
 a pump for conveying the liquid medium and being operably connected to and driven by said electric motor, said pump being only partially radially inside of said stator, said pump having a shaft and an eccentric internal geared wheel, said shaft having a pinion opposite to and meshing with said eccentric internal geared wheel; 
 a housing enclosing said electric motor and said pump, wherein said meshing gear is on an end of said rotor that is opposite to said pump, and wherein said meshing gear engages with said shaft thereby allowing said rotor to drive said shaft; 
 an inlet and an outlet, said inlet and outlet being positioned on opposite ends of the pumping unit from each other, wherein said rotor has at least one axial bore therethrough that provides fluid communication between said inlet and said outlet; and 
 an annular-shaped intermediate space between said rotor and said stator, wherein said annular-shaped intermediate space provides fluid communication between said inlet and said outlet. 
 
   
   
     4. The pumping unit of  claim 3 , wherein said stator has a stator winding and a stator sheet stack, wherein said pump is only partially radially inside of said stator winding, and wherein said rotor is inside of said stator sheet stack. 
   
   
     5. The pumping unit of  claim 3 , wherein said rotor has a central bore, wherein said shaft has a first segment that is in said central bore, and wherein between said first segment and said rotor in said central bore is at least one spacer sleeve. 
   
   
     6. The pumping unit of  claim 5 , wherein said shaft has a second segment adjacent to said first segment, wherein said second segment is connected to said pinion inside of said pump, and wherein said first segment has a first diameter that is smaller than a second diameter of said second segment. 
   
   
     7. A method of pumping a liquid medium comprising:
 providing a rotor of an electric motor at a first end of a housing; 
 positioning a pump partially inside of a stator of said electric motor at a second end of said housing that is opposite to said first end; 
 providing power to said electric motor to drive said pump via a meshing gear that is connected between a shaft of said pump and said rotor thereby causing flow of the liquid medium from said first end to said second end, wherein said liquid medium flows through an annular-shaped intermediate space between said rotor and said stator; and 
 surrounding said rotor with first and second annular channels on opposing sides of said rotor, wherein said first annular channel is in fluid communication with an inlet of the housing and said second annular channel is in fluid communication with an outlet of said housing. 
 
   
   
     8. The method of  claim 7 , wherein said liquid medium flows through at least one bore in said rotor. 
   
   
     9. The method of  claim 7 , further comprising positioning said pump partially radially inside of a stator winding of said stator, and positioning said rotor inside of a stator sheet stack of said stator. 
   
   
     10. The method of  claim 7 , further comprising positioning said shaft through a central bore of said rotor using at least one spacer sleeve between said shaft and said rotor.